Learn what causes allergies, and what can be done about your annoying runny nose?
Today’s article will cover the subject of seasonal allergies. Many different things cause allergies, but today’s article will focus on the less serious seasonal allergies. I’ll explain the more serious allergies, such as latex, bee stings, and peanut allergies in next week’s article.
What Are Allergies?
So what causes allergies in the first place? Allergies occur when the immune system mistakenly identifies benign substances—like pollen—as dangerous.
How Does the Immune System Work?
The primary soldier of the immune system is the white blood cell. White blood cells fight against external threats in two steps: first they identify the threat, and secondly they destroy that threat.
How does the body know what is and is not a threat? It has pre-programmed ideas in its DNA that tells it what is and is not dangerous. A healthy immune system not only knows not to attack the person’s body, it also knows to ignore things that are not harmful, such as the helpful bacteria in the colon, and foreign proteins from foods we eat. But sometimes the immune system gets it wrong as you’ll see below.
How White Blood Cells and Antibodies Work
Once the white blood cells identify something potentially dangerous, they act to neutralize it. The first defense the body has is in the form of antibodies. Antibodies are special proteins that are present in the bloodstream and in the respiratory and digestive tracts which can recognize unwelcome invaders. (known as pathogens). Each antibody is specially made to recognize only one pathogen on a specific part of that pathogen known as the antigen. An antibody is like a key that will only fit into a certain lock--that lock being the antigen. Once an antibody binds to the antigen on the foreign invader, it calls the white blood cells to neutralize it.
After the antibodies do their duty and mark the bad invaders, white blood cells work by either engulfing them or by breaking them apart into harmless substances. The white blood cells also release substances that alert the rest of the body to do what it can to fight off the dangerous invader. These substances have fancy names like interleukin and leukotrienes, but there is one of them with a name that should sound familiar: histamine.
What Causes Allergic Reactions?
Seasonal allergies occur when the body is invaded by that most dangerous of substances: pollen. The pollen can come from trees, grasses, or other plants, but they happen because the pollen is small enough to float in the air. The body works to fight off airborne invaders by putting up defenses in the respiratory tract, specifically the nose. In certain people, their bodies have decided that pollen is a threat, and so put a bunch of antibodies against the pollen in the person’s nose. The pollen is just trying to make baby trees, it’s not trying to hurt us; but for some reason, the body thinks otherwise. The histamine released causes swelling of the tissue in the nose as well as an increase in mucous production. Histamine also makes you itch.